AIMS:to assess pelvic floor muscle maximum voluntary contraction (MVC) before and after surgical treatment for pelvic organ prolapse (POP). METHODS:This was a prospective observational study with women scheduled for surgical correction of POP. Assessments occurred 15 days before and 40 days after surgery. The primary outcome was pelvic floor muscle (PFM) MVC measured using the manometer Peritron™. The average strength of PFM contraction was also measured. Secondary outcomes were assessed using the Pelvic Organ Prolapse Quantification (POP-Q) score. The Student paired t-test was used for quantitative data. For the pre and postsurgery comparisons of PFM strength in relation to POP-Q value we used the nonparametric Kruskal-Wallis test for dependent variables. The level of significance adopted was P < 0.05. RESULTS:Sixty-seven women were recruited, 65 (97%) completed the study. The mean age of participants was 62 ± 10.2. There was no difference (1.9 cm H2 O ± 12.9; P = 0.22) between MVC before (27.1 cm H2 O ± 17.0) and after surgery (29 cm H2 O ± 17.8). The average contraction was higher after surgery (2.3 cmH2 O ± 8.6; P = 0.03). The higher the severity of pre and postsurgery POP, the worse the MVC. CONCLUSION:There was no difference in MVC pre and postsurgery, however we found an improvement in PFM average contraction strength postsurgery.